package edu.sctu.zhangwang.month201505.day20150525.study;

/**
 * Created by Administrator on 2015/5/25 0025.
 */
public class TestMain {
    public static void main(String[] args) {
        A a1 = new A();
        A a2 = new B();
        B b = new B();
        C c = new C();
        D d = new D();

        a1.show(d);
        a2.show(c);
        a2.show(d);
    }
}
